AU1713999A - Alpha-amides of (l)-amino acids as fragrance precursors - Google Patents

Description

WO 99/30679 PCT/US98/25906 -1 ac-AMIDES OF L-AMINO ACIDS AS FRAGRANCE PRECURSORS The invention relates to a-amides of L-amino acids that are precursors of fragrances and which are useful in the formulation of deodorants, antiperspirants, body sprays, and other skin treatment compositions. 5 In humans, axillary malodors are produced by enzymatic cleavage of malodor precursors found in apocrine secretions. The enzymes that release the malodors are produced by axillary bacteria such as Staphylococcus sp. and Corynebacteria. Typical deodorants mask or decrease this malodor. It has now been shown that various a-amides of L-amino acids can 10 be cleaved by axillary bacterial enzymes, releasing pleasant fragrances and/or attenuating malodor. Such amino acid amides, therefore, are useful in skin treatment compositions such as deodorants, antiperspirants, and body sprays. Accordingly, the invention relates to a-amides of L-amino acids that are precursors of fragrances, or which can attenuate or mask malodor. 15 In one aspect, the invention features a skin treatment composition (e.g., a deodorant composition) for application to human skin; the skin treatment composition includes a dermatologically acceptable vehicle and an a-amide of an L-amino acid having the structure:

R

2

C(O)-NH-CH-CO

2 H 20 RI wherein R 1 is H, CH 3 , CH 2 OH, or CH 2

(OH)CH

3 ; and R 2 is selected so that cleavage of the ac-amide of the L-amino acid leaves an R 2

-CO

2 H having a neutral or pleasant odor, or which is useful in attenuating or masking malodor. In general, these 25 ac-amides of L-amino acids are cleaved by bacterial enzymes by the reaction shown below. R, I

R

2

-C(O)-NH-CH-CO

2 H -+ H 2

N-C-CO

2 H + R 2 COOH 30 R, The ac-amide of the L-amino acid is present in an amount sufficient to produce fragrance or attenuate or mask malodor. Preferably, the a-amide of L-amino acid is present in the skin treatment composition at a concentration of 0.01 WO 99/30679 PCT/US98/25906 -2 to 10.0% (preferably 0.1 to 5.0%) by weight. If desired, the skin treatment composition can include an antiperspirant active (e.g., aluminum chlorohydrate) or a deodorant active (e.g., an antimicrobial). In various preferred embodiments, the skin treatment composition is formulated as a lotion, cream, stick, gel, or aerosol. 5 The composition may be formulated as a skin moisturizer, shampoo, shave preparation, body spray, body wash, soap, and the like. The invention offers several advantages. For example, when the a-amides of L-amino acids are formulated as skin treatment compositions, fragrance is released slowly over time. Consequently, the fragrance is long-lasting and fading 10 of the scent over time is minimized. In many instances, the ac-amide of L-amino acid competes with the malodor precursor and attenuates malodor production over a prolonged period. Other features and advantages of the invention will be apparent from the following detailed description, and from the claims. 15 In preferred a.-amides of L-amino acids, R 2 has 1 to 30 carbon atoms and is alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, aryl or heterocyclic. These groups may be unsubstituted or substituted with one or more halo, hydroxyl, amino, nitro, amide, alkoxyl, carboxyl, cyano, thio, phosphoro, or other heteroatoms, phenyl or heterocyclic groups. The amino, amide, alkoxyl, carboxyl, thio, 20 phosphoro, phenyl, or heterocyclic groups may be unsubstituted or substituted with one or more halo, hydroxyl, amino, nitro, alkyl, amide, alkoxyl, carboxyl, cyano, thio, or phosphoro groups.

R

2 can be, for example, methyl, ethyl, propyl, isopropyl, tert-butyl, sec-butyl, isobutyl, n-butyl, pentyl, hexyl, heptyl, octyl, 2-octyl, nonyl, 2-nonyl, 25 decyl, 2-decyl, undecyl, 2-undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, or octadecyl, or any mono or poly unsaturated form thereof, cyclopentyl, cyclohexyl, 2-cyclohexylethyl, 2,6-dimethylheptyl, geranyl, neryl, citronellyl, 9-decenyl, 2,6-dimethyl-5-heptenyl, 2,6-dimethyl-1,5-heptadienyl, 8,11-heptadecadienyl, 8-heptadecenyl, cyclopentenyl, cyclohexenyl, phenyl, 30 p-methoxy-phenyl, benzyl, 2-phenylethyl, 1-phenylethyl, 2-(p-methoxyo phenyl)-ethenyl, 3-(p-methylphenyl)-2-propyl, 3-(p-isopropylphenyl)-2-propyl, 3-(p tert-butyl-phenyl)-2-propyl,2,5,8-trioxanonyl, acetonyl, aminomethyl, WO 99/30679 PCT/US98/25906 -3 hydroxymethyl, 1-hydroxyethyl, dimethylaminomethyl, 1-phenyl-l1-aminoethyl, carboxymethyl, 2-carboxyethyl, 3-carboxypropyl, 4-carboxybutyl, 5-carboxypentyl, 6-carboxyhexyl, 7-carboxyheptyl, 8-carboxyoctyl, 9-carboxynonyl, 10-carboxy 2,5,8-trioxanonyl, 7-carboxamido-5-carboxy-4-aza-3-oxo-heptyl, 8-carboxamido-6 5 carboxy-5- aza- 4-oxo-octyl, 9-carboxamido-7-carboxy-6-aza-5-oxo-nonyl, 10-carboxamido-8-car- boxy-7-aza-6-oxo-decyl, 11-carboxamido-9-carboxy 8-aza-7-oxo-undecyl, 14-carboxamido- 12-carboxy- 11-aza- 10-oxo-tetradecyl, 2-pentyl-cyclopropyl, menthyl, or terpineyl. Preferred a-amides of L-amino acids for use in the invention include, 10 without limitation, N-methylpentenylserine, N-methylpentenylalanine, N-phenyl acetylserine, N-phenylacetylalanine, N-indolacetylserine, N-indolacetylalanine, N-cyclohexylcarboxylserine, N-cyclohexylcarboxylalanine, N-ethylbutyrylserine, N-ethylbutyrylalanine, N-phenylpropionylserine, N-phenylpropionyl alanine, N-benzoylserine, N-benzoylalanine, N-cyclohexylacetylserine, N-cyclohexylacetyl 15 alanine, N-vanilloylserine, N-vanilloylalanine, N-methylpentenyl threonine, N-methylpentenylglycine, N-phenylacetylthreonine, N-phenylacetylglycine, N-indol acetylthreonine, N-indolacetylglycine, N-cyclohexylcarboxylthreonine, N-cyclo hexylcarboxylglycine, N-ethylbutyrylthreonine, N-ethylbutyrylglycine, N-phenyl propionylthreonine, N-phenylpropionylglycine, N-benzoylthreonine, N-benzoyl 20 glycine, N-cyclohexylacetylthreonine, N-cyclohexylacetylglycine, N-vanilloyl threonine, N-vanilloylglycine. The preferred ax-amides of L-amino acids generally can be prepared by coupling a carboxylic acid to a protected amino acid by known procedures. The carboxylic acids and protected amino acids generally are known in the art; they 25 generally are either commercially available or can be made by known procedures. Examples Various (x-amides of L-amino acids were synthesized and tested for cleavage by Staphylococcus haemolyticus, which is commonly found on human skin, especially in the axilla. In the following examples, amide analogs of the amino 30 acids serine and alanine in which R 2 was phenylacetic acid (PAA) or methyl pentenoic acid (MPA) were synthesized. Other known fragrant carboxylic acids (e.g., ethylbutyric acid, cyclohexylcarboxylic acid, or indole-3-acetic acid) can be WO 99/30679 PCT/US98/25906 -4 substituted for PAA or MPA. The o-amides of the L-amino acids were synthesized as described below. The following working examples also provide general guidance for synthesis and testing of other c-amides of L-amino acids in accordance with the invention. These examples are meant to illustrate, not limit, the invention, the 5 metes and bounds of which are defined by the claims. Synthesis of c-Amides of L-Amino Acids Coupling Carboxvlic Acids to Protected Amino Acids: To couple the carboxylic acid to a protected amino acid (e.g. O-t-butylserine t-butylester-HC1, alanine methyl ester hydrochloride) the carboxylic acid (7.4 mmol), the protected 10 amino acid (7.1 mmol), 4-dimethylaminopyridine (0.1 g), diisopropylethylamine (0.92 g, 7.1 mmol) and methylene chloride (40 mL) were stirred, under nitrogen in a 100 mL flask, until the amino acid was dissolved. The reaction was cooled in an ice-water bath and a solution of dicyclohexylcarbodiimide (DCC) (1.5 g 7.3 mmol) dissolved in methylene chloride (20 mL) was added. Stirring was continued in the 15 ice water bath for approximately 15 minutes, during which time a white precipitate of dicyclohexylurea (DCU) began to form. The reaction was then stirred overnight at room temperature under nitrogen. The following day, the DCU was suction filtered off, and the filtrate was washed twice with 50 mL of 10% sodium bicarbonate, washed twice with IM hydrochloric acid (50ml) then washed once with 20 50 mL of saturated sodium chloride. The organic layer was dried over anhydrous magnesium sulfate for at least two hours, filtered, and rotary evaporated to dryness. The product can be analyzed with thin layer chromatography (TLC, using silica gel plates) in order to determine the optimal solvent for purification via flash chromatography (e.g., with the FLASH 40 system from Biotage). In general 25 30-40% ethyl acetate/hexane is suitable. Dissolution of the product prior to chromatography in the eluting solvent may leave additional DCU undissolved, which can be suction-filtered off. Removal of the Methyl Ester Protecting Group: To remove the methyl ester protecting group, the N-acylamino acid methyl ester (approximately 5 mmol), 95% 30 ethanol (15 mL), and 10 OM potassium hydroxide (15 mL) were stirred at room temperature for approximately one hour. The solution was then cooled in an ice water bath and acidified to pH 1-2 with 10OM hydrochloric acid. The solution was WO 99/30679 PCT/US98/25906 -5 extracted with chloroform (2x50 mL) after adding a minimum amount of water to dissolve the potassium chloride formed during the acidification. The organic layers were combined and dried over anhydrous magnesium sulfate for several hours. After filtering off the solids, the filtrate was rotary evaporated, followed by 5 vacuum-oven drying at room temperature. Removal of the t-Butvl Ether and Ester Protecting Groups: The protected amino acid (approximately 10 mmol) was dissolved in trifluoroacetic acid (TFA; 25 mL), and the solution was stirred at room temperature for approximately 3 hours (until the reaction was completed, as determined by TLC using the solvents 10 identified for chromatographic purification). The TFA was removed via rotary evaporation and vacuum-oven drying. In an alternative method, the protected amino acid (10 mmol) was dissolved in ethyl acetate (25 mL), the solution was cooled in an ice-water bath, and hydrogen chloride gas was bubbled into the solution for approximately 15 minutes. 15 The ice-water bath was removed, and the solution was stirred overnight. The solvent then was removed by rotary evaporation and vacuum-oven drying. The products from the reactions were analyzed by TLC on silica gel plates and by 'H NMR with a Bruker AC-250 NMR Spectrometer. Assay of the a-Amides Of L-Amino Acids for Cleavage by Bacteria 20 The synthesized a-amides of L-amino acids were tested for their ability to be cleaved by bacteria normally found in human axilla. For this example, a 100 mL culture of Staphylococcus haemolyticus was grown overnight at 37 0 C in Trypticase Soy Broth medium. The cells were pelleted by centrifuging the culture at 5,000 rpm for 12 minutes, and the pelleted cells were resuspended in sterile 25 saline. The cells were again pelleted and resuspended in sterile saline. After pelleting the cells once again, the cells were weighed and resuspended in sterile assay buffer (50 mM phosphate, pH 6.8, 1% glucose/dextran). The final concentration of cells was 0.05 g cells/mL (for the gas chromatography (GC) assay) or 0.1 g cells/mL (for the NMR assay). These cell suspensions can be stored at 30 4 0 C. The a-amides of L-amino acids were prepared as stock solutions at a concentration of approximately 5 mg/mL in 50 mM potassium phosphate buffer (pH WO 99/30679 PCT/US98/25906 -6 6.8). If necessary, the pH can be adjusted to 6.8-7.0 with 1N NaOH. The amino acid stock solutions were sterilized by filtering them through 0.22 pm filters. Gas Chromatography Assay To demonstrate that the c-amides of L-amino acids can be cleaved by 5 bacteria normally found in axilla, a 100 pL aliquot of the ca-amide of L-amino acid stock was added to 100 ptL of cells in sterile tubes. For a negative control, the cells were incubated with 100 pL sterile phosphate buffer. The samples were incubated for 16-18 hours at 37 0 C, and the reactions were quenched with 10 [tL of 10 N HC1. The samples then were extracted with 100 [tL chloroform and analyzed by gas 10 chromatography. NMR Assay In addition to analyzing the cleavage reactions by gas chromatography, NMR analysis was used. A 500 jiL aliquot of the a-amide of the L-amino acid stock solution was added to 500 pL of cells in sterile tubes. The cells 15 and a-amides of L-amino acids were incubated for 16-18 hours at 37oC, with shaking, and the cleavage reactions were quenched with 50 p1L of 10 N HC1. Each sample then was extracted with 600 pL of CDC1 3 , and the extracts were filtered through a Na 2

SO

4 pipette filter to remove water from the samples. 'H NMR spectra of the samples then were taken (64-128 scans generally is sufficient), zooming in on 20 a region that would contain peaks from the cleavage product. The presence or absence of these peaks allowed for a qualitative determination of whether the c-amides of L-amino acids were cleaved. Each of the a-amides of L-amino acids (phenylacetylalanine, methylpentenylalanine, and methylpentenylserine) was cleaved by the Staphylococcus haemolyticus cells, as determined by gas chromatography or 25 'H NMR. Thus, these a-amides of L-amino acids can be used as fragrance pre cursors in skin treatment compositions. Formulation of Skin Treatment Compositions A variety of skin treatment (e.g., deodorant or antiperspirant) compositions are known in the art, and the a-amides of L-amino acids of the 30 invention can be used in the formulation of such skin treatment compositions. A variety of skin treatment compositions can be made that include an effective amount of the a-amides of L-amino acids in a dermatologically acceptable vehicle. Such WO 99/30679 PCT/US98/25906 -7 vehicles for use in deodorant or antiperspirant compositions and other ingredients that can be used in deodorant or antiperspirant compositions are known in the art. A preferred form is one containing a deodorant active (e.g. an antimicrobial). Another preferred form is one containing an antiperspirant active. The a-amides of 5 L-amino acids of the invention are used in an amount sufficient to produce fragrance or attenuate or mask malodor when the skin treatment composition is applied topically to skin. Suitable formulations also are well known in the art. Generally, the c-amides of L-amino acids are used at a concentration of 0.01 to 10%, preferably 0.1 to 5.0%, by weight. A single a-amide of an L-amino acid can 10 be used in a skin treatment composition, or multiple o-amides of L-amino acids can be used in combination. Examples of suitable deodorant actives include, without limitation, triclosan, triclocarban, zinc phenolsulfonate, other zinc salts, lichen extract, and usnic acid. Examples of suitable antiperspirant actives include, without limitation, 15 salts of aluminum chlorohydrate; aluminum sesquichlorohydrate, aluminum dichlorohydrate, aluminum chlorohydrex PG or PEG, aluminum sesquichlorohydrex PG or PEG, aluminum dichlorohydrex PG or PEG, aluminum zirconium trichloro hydrate, aluminum zirconium tetrachlorohydrate, aluminum zirconium tetra chlorohydrex PG or PEG, aluminum zirconium pentachlorohydrate, aluminum 20 zirconium octachlorohydrate, aluminum zirconium trichlorohydrex-gly, aluminum zirconium tetrachlorohydrex-gly, aluminum zirconium pentachlorohydrex-gly, aluminum zirconium octachlorohydrex-gly, aluminum zirconium chloride, aluminum zirconium sulfate, WO 99/30679 PCT/US98/25906 -8 Deodorant Stick Ingredients %w/w Propylene glycol 70.300 Water 20.500 5 Sodium Stearate 7.000 Triclosan 0.300 Fragrance 1.400 ca-amide of L-amino acid 0.50 Total 100.00 10 Aerosol Antiperspirant Ingredients %w/w Cyclomethicone 10.0 Dimethicone 2.0 15 Cyclomethicone (and) Quaternium 18 Hectorite (and) SDA 40 2.0 SDA 40, Anhydrous 0.5 Aluminum Chlorohydrate 10.0 a-amide of L-amino acid 1.0 20 Propellant A-31 74.5 Total 100.00 Suspension Antiperspirant Stick Ingredients %w/w 25 Cyclomethicone 54.5 Stearyl Alcohol 20.0 PPG-14 Butyl Ether 2.0 Hydrogenated Castor Oil 1.0 Talc 2.0 30 Aluminum Zirconium Tetrachlorohydrex-Gly 20.0 c-amide of L-amino acid 0.5 Total 100.00 WO 99/30679 PCT/US98/25906 -9 Anhydrous Roll-On Antiperspirant Ingredients %w/w Cyclomethicone 69.0 Dimethicone 5.0 5 Cyclomethicone (and) Quaternium 18 Hectorite (and) SDA 40 3.0 SDA 40, Anhydrous 2.5 Aluminum Zirconium Tetrachlorohydrex-Gly 20.0 ca-amide of L-amino acid 1.0 10 Fragrance Oil q.s. Total 100.00 Transparent Antiperspirant Gel Ingredients %w/w 15 Phase A Cyclomethicone (and) Dimethicone Copolyol 10.0 Cyclomethicone 7.0 Phase B Aluminum Chlorohydrate (and) Water 50.0 20 Propylene Glycol 16.0 Water 16.0 ca-amide of L-amino acid 1.0 Total 100.00 25 Nonionic O/W, Emollient Cream Ingredients %w/w Water 73.000 Stearic acid 7.200 Glyceryl monostearate 4.500 30 Lanolin 1.000 Isopropyl myristate 4.300 Polyethylene glycol 1000 monostearate 6.000 WO 99/30679 PCT/US98/25906 -10 Propylene glycol 2.500 ca-amide of L-amino acid 1.00 Preservative 0.300 Perfume 0.200 5 Total 100.00 Other Embodiments If desired, the a-amides of L-amino acids can be used in combination with other fragrance producing molecules or perfumes as indicators that the products are working, or to enhance the fragrance. In addition, the ca-amides of 10 L-amino acids can be used in personal care compositions to produce fragrance or attenuate or mask malodors. It is to be understood that while the invention has been described in conjunction with the detailed description thereof, the foregoing description is intended to illustrate and not limit the scope of the invention, which is defined by 15 the scope of the appended claims. Other aspects, advantages, and modifications are within the scope of the following claims.

Claims (12)

1. A composition for application to human skin comprising a dermatologically acceptable vehicle and an ax-amide of an L-amino acid having the structure: 5 R 2 C(O)-NH-CH-CO 2 H I R, wherein: he a the a-amide of the L-amino acid is present in an amount sufficient to 10 produce fragrance or attenuate or mask malodor; R 1 is H, CH 3 , CH 2 OH, or CH 2 (OH)CH 3 ; and R 2 is selected so that cleavage of the a-amide of the L-amino acid leaves an R 2 -CO 2 H having a neutral or pleasant odor.

2. The composition of claim 1, wherein R 2 has 1 to 30 carbon atoms 15 and is alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, aryl, or heterocyclic, wherein each of these may be unsubstituted or substituted with one or more halo, hydroxyl, amino, nitro, amide, alkoxyl, carboxyl, cyano, thio, phosphoro, phenyl, or heterocyclic groups, wherein the amino, amide, alkoxyl, carboxyl, thio, phosphoro, phenyl, or heterocyclic groups may be unsubstituted or substituted with one or more 20 halo, hydroxyl, amino, nitro, amide, alkyl, alkoxyl, carboxyl, cyano, thio, or phosphoro groups.

3. The composition of claim 2, wherein R 2 is methyl, ethyl, propyl, isopropyl, tert-butyl, sec-butyl, isobutyl, n-butyl, pentyl, hexyl, heptyl, octyl, 2-octyl, nonyl, 2-nonyl, decyl, 2-decyl, undecyl, 2-undecyl, dodecyl, tridecyl, 25 tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, or a mono or poly unsaturated form of any of the foregoing, cyclopentyl, cyclohexyl, 2-cyclo hexylethyl, 2,6-dimethylheptyl, geranyl, neryl, citronellyl, 9-decenyl, 2,6-dimethyl-5-heptenyl, 2,6-dimethyl-1,5-heptadienyl, 8,11-heptadecadienyl,

8-heptadecenyl, cyclopentenyl, cyclohexenyl, phenyl, p-methoxyphenyl, benzyl, 30 2-phenylethyl, 1-phenylethyl, 2-(p-methoxyophenyl)-ethenyl, 3-(p-methyl phenyl)-2-propyl, 3-(p-isopropylphenyl)-2-propyl, 3-(p-tert-butyl phenyl)-2-propyl,2,5,8-trioxanonyl, acetonyl, aminomethyl, hydroxymethyl, 1-hydroxyethyl, dimethylaminomethyl, 1-phenyl-l1-aminoethyl, carboxymethyl, WO 99/30679 PCT/US98/25906 - 12 2-carboxyethyl, 3-carboxypropyl, 4-carboxybutyl, 5-carboxypentyl, 6-carboxyhexyl, 7-carboxyheptyl, 8-carboxyoctyl, 9-carboxynonyl, 10-carboxy-2,5,8-trioxanonyl, 7-carboxamido-5-carboxy-4-aza-3-oxo-heptyl, 8-carboxamido-6-carboxy-5-aza 4-oxo-octyl, 9-carboxamido-7-carboxy-6-aza-5-oxo-nonyl, 10-carboxamido 5 8-carboxy-7-aza-6-oxo-decyl, 11-carboxamido-9-carboxy-8-aza-7-oxo-undecyl,

14-carboxamido- 12-carboxy- 11-aza- 10-oxo-tetradecyl, 2-pentyl-cyclopropyl, menthyl, or terpineyl. 4. The composition of claim 1, wherein the a-amide of the L-amino acid is selected from the group consisting of N-methylpentenylserine, 10 N-methylpentenylalanine, N-phenylacetylserine, N-phenylacetylalanine, N-indolacetylserine, N-indolacetylalanine, N-cyclohexylcarboxylserine, N-cyclo-hexylcarboxylalanine, N-ethylbutyrylserine, N-ethylbutyrylalanine, N-phenylpropionylserine, N-phenylpropionylalanine, N-benzoylserine, N-benzoylalanine, N-cyclohexylacetylserine, N-cyclohexylacetylalanine, 15 N-vanilloylserine, N-vanilloylalanine, N-methylpentenylthreonine, N-methylpentenylglycine, N-phenylacetylthreonine, N-phenylacetylglycine, N-indolacetylthreonine, N-indolacetylglycine, N-cyclohexylcarboxylthreonine, N-cyclohexylcarboxylglycine, N-ethylbutyrylthreonine, N-ethylbutyrylglycine, N-phenylpropionylthreonine, N-phenylpropionylglycine, N-benzoylthreonine, 20 N-benzoylglycine, N-cyclo- hexylacetylthreonine, N-cyclohexylacetylglycine, N-vanilloylthreonine, and N-vanilloylglycine. 5. The composition of claim 4, wherein the cc-amide of L-amino acid is N-methylpentenylserine. 6. The composition of claim 4, wherein the c-amide of L-amino acid is 25 N-methylpentenylalanine. 7. The composition of claim 4, wherein the ca-amide of L-amino acid is N-phenylacetylalanine. 8. The composition of claim 1, wherein R 1 is H. 9. The composition of claim 1, wherein R, is CH 3 . 30 10. The composition of claim 1, wherein R, is CH 2 OH. 11. The composition of claim 1, wherein R, is CH 2 (OH)CH 3 . 12. The composition of claim 1, wherein an a-amide of an L-amino acid WO 99/30679 PCT/US98/25906 - 13 is present at a concentration of 0.01 - 10.0% by weight. 13. The composition of claim 1, 8, 9, 10, 11, or 12, further comprising an antiperspirant active. 14. The composition of claim 1, 8, 9, 10, 11, or 12, further comprising a 5 deodorant active.

15. The composition of claim 1, in the form of a lotion, cream, stick, gel, or aerosol.

16. The composition of claim 13, in the form of a lotion, cream, stick, gel, or aerosol. 10 17. The composition of claim 14, in the form of a lotion, cream, stick, gel, or aerosol.

18. A method for producing fragrance or attenuating or masking malodor, the method comprising applying the composition of claim 1, 8, 9, 10, or 11 to skin of a human. 15 19. A method for producing fragrance or attenuating or masking malodor, the method comprising applying the composition of claim 1, 8, 9, 10, or 11 to the axilla of a human.

20. A method for producing fragrance or attenuating or masking malodor, the method comprising applying the composition of claim 13 to skin of a human. 20 21. A method for producing fragrance or attenuating or masking malodor, the method comprising applying the composition of claim 14 to skin of a human.

22. The composition of claim 1, wherein the composition is in the form of a skin moisturizer, shampoo, body wash, soap, shave preparation, or body spray.

23. The composition of claim 22, wherein the ct-amide of the L-amino 25 acid is present at a concentration of 0.01-10.0% by weight.

24. A method for producing fragrance or attenuating or masking malodor, the method comprising applying the composition of claim 22 to skin of a human.